It's difficult to tell from your screenshots - despite the 48MB download (damn, I hate RTF...), your document won't open on AbiWord and crashes LibreOffice (at least on my system), so I can only see things briefly before they die... I think you have a corruption in the fourth page. Using something like snag.gy would perhaps be easier.
Broadly, you should have:
1. A tuner definition that shows that the tuner is recognised by the system. That tuner is associated with...
2. A network definition. This would normally be "Freesat", "Terrestrial", "Brian" or something simple that means something to you - it's just a way of separating networks. You have a much longer name here.
3. Mux definitions. These are the carrier signals broadcast on that network, and thus picked up by the associated tuner. They can be defined by hand or auto-detected if you "seed" the definitions with the basic parameters. There are pre-defined lists, but they're from public sources and are frequently hopelessly out of date.
4. Services. These are then the individual streams available within those muxed carrier signals. These are automatically detected on a scan.
5. Channels. These are the logical groupings of services. You can map these by hand or simply auto-map all discovered services.
The repair work is - was - really just a matter of making sure all these were in place, as that's the significant change between 3.x and 4.x. From what I can see before things crash, thought, it looks to me as if you have most of these, as you have a list of services that appear to be mapped to channels, so I'm not sure that's your problem.
What I can see is that your EPG/XMLTV configuration is complaining, but I don't see that's immediately relevant. After that, we need to start trying to play individual services (so the "Play" link off that tab) or channels (similar) to see what goes on. It may be that your config has been imported without the underlying pieces all being lined up (unlikely if you've rebuilt it)...
68 muxes seems a lot - is this normal for ATSC? It looks like anything with a TSID == 65535 has failed completely, but anything else has returned services and has those services mapped. That said, it's those "with mapped stuff" muxes that are showing in your syslog errors, so there's still something deeper.
Any chance of screenshots (via a paste site and embedded or linked, please) for the whole config - tuners and networks as well as the mux list?
